DESCRIPTION (Adapted from Phase II application abstract): The project proposed in this Phase II application has a broad, long-term objective to develop a user friendly software program, VOL-3D, which models and evaluates the optics of a real and/or user-defined eye and stores analysis outcomes in a relational data base. The software program will use ray tracing and traditional paraxial analysis of the composite model eye. The program will allow, but not require, exam data from commercially available ophthalmic instruments as input in the construction of the model of an individual's eye. The specific aims of Phase II are to capitalize on the Phase I demonstration of feasibility to: 1) expand the library of callable functions; 2) obtain independent verification of modeling assumptions and implementation; 3) optimize the user friendliness; and 4) develop ophthalmic instrumentation interface software modules. This program is related to human health in that it will provide: 1) outcome predictions of surgical and non-surgical interventions; 2) development and optimization of strategies for the optical correction of the eye; 3) education of clinicians and students of visual science; and 4) fundamental research into limitations of the dioptrics of the eye. PROPOSED COMMERCIAL APPLICATION: The software program VOL-3D will be purchased and used by clinicians, vision researchers, owners of corneal topography systems, students, teachers, and companies who are attempting to understand in a predictive manner the optical properties of the eye.